Posted
by
timothy
on Saturday May 22, 2010 @11:04PM
from the let's-go-dutch-this-time dept.

coondoggie writes "The US Air Force said it was looking to launch its 14-foot long X-51A Waverider on its first hypersonic flight test attempt May 25. The unmanned X-51A is expected to fly autonomously for five minutes, after being released from a B-52 Stratofortress off the southern coast of California. The Waverider is powered by a supersonic combustion scramjet engine, and will accelerate to about Mach 6 as it climbs to nearly 70,000 feet. Once flying, the X-51 will transmit vast amounts of data to ground stations about the flight, then splash down into the Pacific. There are no plans to recover the flight test vehicle, one of four built, the Air Force stated."

Actually, there is a vast amount of data that could be applicable to civilian transport. If they can indeed get scramjets really working - and by really, I mean around five times fast as this bad boy, it could mean a DRASTIC price reduction to get things into orbit. A scramjet needs to get to about mach 25 to reach escape velocity, which is significantly faster than this test, but give it time. Let them run this thing, let them run data and the next one might be looking at another mach or two and so on.

15 to 20? Citation needed there. That is between 2000-3000 lbs on a 150 pound person. Fighter pilots have to train to maintain high Gs, which even then they only pull for a matter of seconds (at the highest levels) when flying, and for maybe a few minutes in a centrifuge. They have to wear g-suits to avoid blacking out. Early on during the Korean war, the Mig pilots from the North didn't have g-suits. So the American pilots quickly figured out that if you just get them to follow you into a very high g turn they would black out and crash.

If you want the power output of a rocket engine you need your oxidiser to be concentrated, which is not going to be easy to do even at mach 6. After finally running the numbers a hydrogen/oxygen rocket may work out better.

A scramjet needs to get to about mach 25 to reach escape velocity, which is significantly faster than this test, but give it time.

A scramjet needs to get to about mach 25 within the atmosphere get to orbit. This means it will either have to accelerate stupidly fast or stay low for too long and burn up. It seems to me that it would be better to go mach 10, leave the atmosphere, and go by rocket the rest of the way.

The atmosphere ends before gravity has diminished significantly. We're 6000km+ from the center of gravity, and a mere 100km out I can guarantee you that the engine won't work (likely it won't work higher than 20km). 6000km vs. 6100km just isn't going to make a significant difference.

And again, escape velocity is much worse. I'm only talking about getting to orbit.

Yeah, for air breathing engines you would need a long run in the atmosphere to get anywhere near escape velocity. I don't think we are anywhere near the mach 25-30+ we would need. Air friction is a serious problem. Even the SR-71 was highly designed to cope with the increased temperatures. The X-15 basically flew into the very upper reaches of the atmosphere (to the point of nearly losing any sort of control, and a few of them did) just to contend with the heat and friction. Look at the shielding capsules u

I'm not sure it will do anything with civilian air transport. I don't see this as cutting air drag, which goes up to the fourth power as speed increases, and increases fuel consumption. It probably wouldn't go transcontinental because of noise & sonic boom issues.

Concorde tickets were $10,000 from NY to Europe and the operators often lost money flying it. The manufacturers lost money building the airplanes. A regular sub-sonic flight is $300. Unless scramjet can somehow manage to fly around $1000 a

Don't count on it. The major focus now is to make travel less wasteful (not only making aircraft more efficient, also supplanting them with high speed rail where that's applicable...and where there's a will to do it). Perhaps in a few decades we might have something merely supersonic, with speeds comparable to Concorde, but also more compatible with the really real world.

This thing from TFA...mostly a nice first stage for orbital launches, I guess.

But you still need lots of additional energy for a "hop" of appreciable lenght; pointing your nose up is not enough. Lots of additions / modifications...not that far from "first stage to orbit" that I mentioned. Plus quite small and expensive.

And all this in a world which seem to try being a bit more sustainable; with high speed communication networks more and more prevalent.

Indeed, I never figured out why the Concorde was banned in America. Unless it was purely for economic protectionism. Mythbusters tested sonic booms and they had to fly like 100 feet over a shed to blow out the windows. They started at 1000 feet and got no result. I think the Concorde flew a little higher than that.

According to the wikipedia article on the concorde, it was actually quieter than many other models in service at the time.

I can confirm that.

At one time I lived directly under the flight path to Darwin Airport (in Australia). That airport is also the local Air Force base and runway, so we had not only Boeing 747s and other passenger planes flying directly overhead at an altitude of less than 500 feet, but we also had Air Force Mirages on the same flight path.

During the time I lived there, the Concorde visited, landing and taking off twice (or it might have been 3 times). I'll tell you straight, the Concorde made less noise on take-off than the Jumbo (and they were much quieter than the Mirages).

I'll tell you straight, the Concorde made less noise on take-off than the Jumbo (and they were much quieter than the Mirages).

I would take an educated guess that it's because at take-off the Concorde engines are running very much under capacity, whereas a 747 at take-off is running its engines close to capacity. Much like how a fan in a 1U server screams just to push the same amount of air that a larger fan in a 4U server does leisurely.

It was banned on and off throughout its career. It didn't do too many supersonic flights in the states even when it was allowed. It wasn't even that loud on takeoff, and flew higher than regular airliners.

It seriously annoys me that people take Mythbusters psuedo-scientific results and applies them to everything possible - they used the F/A-18A, which at 35,000lb would be 1/10th the weight of Concorde (and I bet that the F/A-18A in the test had a significantly lower loading than that), and the test was done at significantly lower speeds than Concorde cruises at.

I am doubtful as to the validity of the results the Mythbusters came up with, as it was already proven during the Oklahoma City Sonic Boom tests in 1964 caused hundreds of broken windows (windows in skyscraper structures were broken routinely over the course of the tests, with no significant occurances before and after the tests - make your own conclusions).

Apart from physical damage, you seriously have to consider the environmental impact - can people live with loud bangs as a routine? Again, the Oklahoma City tests showed that no, people are not willing to put up with routine sonic booms as they are disruptive and invasive.

..accept it, is to go and get this baby. It should fetch a good price on ebay. I can only imagine the difficulties of finding this craft in the Pacific Ocean, but if you could... Legend status is yours.

There are no plans to recover the flight test vehicle, one of four built, the Air Force stated."

I would suspect that there is some secret stuff in this plane....so unless it plans on breaking up into a huge fireball right before it hits the ocean.....wouldn't it be foolish to drop something like that and not retrieve it?

The concept is not new but it is very difficult to turn it into practice. These guys at University of Queensland and others have been working on this for several years and have trialled severa prototypes before.
http://www.uq.edu.au/news/index.html?article=20718 [uq.edu.au]
Not bad without military budgets - beat them to the punch!

"Published: 27 February 2010... Professor Boyce said the project represented the first phase of a 20-year program that ultimately would include ground testing, the development of new materials and flight testing at Woomera, South Australia"

From Wikipedia and the summary:

"Ground tests of the X-51A began in late 2006.""The US Air Force said it was looking to launch its 14-foot long X-51A Waverider on its first hypersonic flight test attempt May 25."

On top of that, the GGP claims "Not bad without military budgets" when your link states "The launch was a collaborative effort between the United States' Defense Advanced Research Projects Agency (DARPA) and the Defence Science and Technology Organisation (DSTO), also representing the research collaborators in the Australian Hypersonics Initiative (AHI)."

Not to belittle their efforts, mind you; it's a spectacular project and I wis

If there was a plane faster than an SR-71, there's no guarantee that it would be public knowledge.

That said, a fast plane isn't as necessary for spying as it was in the 60's. Who knows what kind of crazy tech is out there doing the hard spy work now, the geek in me hopes that there's something more interesting than satellites...

Given the way that everyone has latched onto that fact, maybe it's been their plan all along. Say you don't want it, wait for someone to salvage it, then buy it back for a token amount. Maybe they're smarter than you think:)

Alternatively, maybe it's not going to end its flight where they say it is...

Yeah so now every time a plane overshoots a runway we have a radiation leak...

Nuclear energy is great for things like space travel and for generating electricity. It isn't so great for earth-bound transportation where it could easily leak. Not to mention the restrictions on a plane. Who cares if it can go from New York to Paris in an hour if it won't be able to be landed in Paris due to the fact it has nuclear material...

And airplanes not only are more prone to those, they also don't enjoy the comfort of generous weight budgets and being essentially buried after any accident.

All of this is beside the point though - experiments with nuclear aircraft propulsion were performed by both the US and Soviet Union (the latter apparently actually had it propelling an aircraft, at least partially). If there's one thing they have shown, it is that even with the small crew

quick! Nobody tell the Navy they've been using numerous nuclear powered aircraft carriers for earth bound travel for almost 50 years without incident!

Insightful? That's the US Navy, not a public or private corporation. Your sarcastic remark would seem to indicate that we could trust corporations to use nuclear technology to create transportation solutions for us.

Well if air travel is any indication, and the massive screw ups there with security theater, maintenance irregularities, cheap greedy bastards th

Depending on how you define a "Nuclear" train, you could have a single, central, fixed location Nuclear power plant, and an electrified rail system (or wires, or a pair of superconducting rails, etc) to power the trains, so there's no reactor on the trains themselves - just electric motors, or maybe a mag-lev propulsion system, etc.

They have had this in France for years [wikipedia.org]. France is largely nuclear powered and sells electricity to it's neighbors. The train is a very sensible tech platform - uses existing rail lines for up to 140mph, and can go up to 200mph on specially graded track. I took the TGV from Paris to Marseille - a few hours for what would have been a six or seven hour drive and at least 3 or 4 hours through an airport.

Most Americans have no idea how convenient rail travel is. I bought my ticket 10 minutes before the train left, and a few minutes after boarding I was enjoying a cup of coffee while I sat in the equivalent of first class on an airplane for about $50. I had a table, a full size restroom nearby, and dining car at my disposal. If you've really got the dough or don't have the time, you can walk on without a ticket and pay the conductor the highest rate.

Planes are still the way to go for cross-continental travel, but a regional electric train system is a no brainer. Well, if you have a society that wants reality based solutions instead of empty rhetoric like "Drill, baby, drill."

Most Europeans have no idea how big America is or how much denser the population of Europe

A majority of Americans live in urban areas. The population density of nearly the entire east coast is comparable to that of Europe.

is or how much train tickets are subsidized

Virtually every road and highway in the United States is constructed with tax dollars.

or how government controlled mass transit allows the government to control where people live and how they move about.

I always thought it was the UFOs or the communist party that lives inside of Pelosi's teeth!

The nuclear power industry in the US was largely killed by environmental activists who were being manipulated by Soviet agents during the cold war... Environmental activists in the US have stifled and curtailed the development of every type of currently viable large scale domestic energy production with the result that the US is much more dependent on foreign energy sources now than it has ever been before.

Is the hospital really allowed to give you unfettered access to the internet?

Just as a similar synthetic rubber corporation helped us win World War II, so will we mobilize American determination and abi

Fortunately that was without a major market upset. You can guess what happens to that trash when funding is removed. Or you can just have a look at the countries of the old USSR to have a very visible example. People are *horrible* at preventing incidents over a long time scale.

We need to find a way to fit nuclear powered engines onto planes if we are to make a leap into next chapter of aviation.

Currently the only things we really know how to do with nuclear energy is heat stuff up (eg turn water to steam to make electricity) and blow stuff up (eg a bomb). Neither of those two things really work well in an airplane... the first is too heavy and the second is bad for business.

"We annually spend on military security more than the net income of all United States corporations.

This conjunction of an immense military establishment and a large arms industry is new in the American experience. The total influence -- economic, political, even spiritual -- is felt in every city, every State house, every office of the Federal government. We recognize the imperative need for this development. Yet we must not fail to comprehend its grave implications. Our toil, resources and livelihood are all involved; so is the very structure of our society.

In the councils of government, we must guard against the acquisition of unwarranted influence, whether sought or unsought, by the military-industrial complex. The potential for the disastrous rise of misplaced power exists and will persist.

We must never let the weight of this combination endanger our liberties or democratic processes. We should take nothing for granted. Only an alert and knowledgeable citizenry can compel the proper meshing of the huge industrial and military machinery of defense with our peaceful methods and goals, so that security and liberty may prosper together.

Akin to, and largely responsible for the sweeping changes in our industrial-military posture, has been the technological revolution during recent decades.

In this revolution, research has become central; it also becomes more formalized, complex, and costly. A steadily increasing share is conducted for, by, or at the direction of, the Federal government.

Today, the solitary inventor, tinkering in his shop, has been overshadowed by task forces of scientists in laboratories and testing fields. In the same fashion, the free university, historically the fountainhead of free ideas and scientific discovery, has experienced a revolution in the conduct of research. Partly because of the huge costs involved, a government contract becomes virtually a substitute for intellectual curiosity. For every old blackboard there are now hundreds of new electronic computers.

The prospect of domination of the nation's scholars by Federal employment, project allocations, and the power of money is ever present and is gravely to be regarded.

Yet, in holding scientific research and discovery in respect, as we should, we must also be alert to the equal and opposite danger that public policy could itself become the captive of a scientific-technological elite. " -- Dwight D Eisenhower, 1961

Those hundreds of electronic computers really beefed up government authority and took power out of the hands of individuals didn't they?
And the solitary inventor, tinkering in his shop/garage, hasn't been able to come up with anything since 1961 right? That's why big government-contract-supported corporations like IBM have prospered while small start-ups have only failed.

Damn this military/government industrial-complex owned world, with all its electronic computers!!

While true government investment in research is vital for our growth and continued economic performance it is not solely responsible for it. The government did start the first internet, but it was business investment that also largely pushed the further development and refinement of the microcomputer.

The solitary inventor is largely pushed out of state of the art engineering. Like it or not much of science and cutting-edge research is a large, time-consuming and labor intensive practice that requires more

(But also as I mentioned above Google, Facebook, Microsoft, etc, etc, were all start-up companies that became huge without any government support; R&D does need huge teams these days but opportunities for the little guy are greater than ever.)

1. My point was that the private sector and the garage inventor have thrived without any government/military help.
That couldn't be further from saying that Facebook on phones couldn't have happened without the military casualties over the last half-century.

2. If only those deaths were for the sake of technological development since the 60s; that would be much better than the grim reality that (for the most part) they were just a terrible waste.

Every strategist remembers Aug. 20, 1998, when the USS Abraham Lincoln Battle Group, stationed in the Arabian Sea, launched Tomahawk cruise missiles at an Al Qaeda training camp in eastern Afghanistan, hoping to take out Osama Bin Laden. With a top speed of 550 mph, the Tomahawks made the 1100-mile trip in 2 hours. By then, Bin Laden was gone -- missed by less than an hour, according to Richard A. Clarke, former head of U.S. counterterrorism.

Yeah but for that you need exact coordinates. It makes getting into a window where we know someone is easier but still wouldn't lead to what you're talking about. Might as well go off on satellite and laser technology for fear of the US deploying "Orbital Death Lasers."

I don't see much of a military need for this tech, however, when we've had military launch capability that could reach any location on earth well within a day, including the time it takes for authorization, for close to half a century.

Well within a day?Because of the global war on terror, people in Bush's Administration proposed puttingconventional munitions on fucking SLBMs so we can have a worldwide response time in minutes.IIRC, Congress repeatedly shot down the idea.

I'm not sure where the funding came from, but Obama/Gates have picked up the idea and run with it.I'd much rather see the military "waste" money on scramjets than repurposing SLBMs/ICBMs.

IIRC, the idea wasn't to put conventional explosives on them, but rather just load them with lead or something else cheap, heavy, and inert and use them as a mass impact weapon. A Trident II missile MIRV comes in at about 6,000m/s. a W88 nuclear warhead supposedly weights about 800lbs. Replace that with 800lbs of lead and when it hits, you'll get as much energy as about a ton and a half of TNT and a Trident can carry up to 12 such loads.

But then again, we are probably on the verge of global resource wars amongst nations that have not.

What a sad state our greed and short sightedness has brought us to. Our capabilities as a species have changed enormously in the last century or so, but our insight into ourselves has not.

BTW, US seems to put itself in a, well, curious situation. With population so used to overconsumption relying on foreign resources (while largely preserving "domestic" caches of...the same resources), it's bound to end in confrontation sooner or later. Not saying that it will be very disastrous for the US, oh no - with the amount of resources wasted on "defense" (nice newspeak btw) industry, it should do reasonably fine; but it still might be nasty, also locally (and certainly when looking at humanity...);

I don't see much of a military need for this tech, however, when we've had military launch capability that could reach any location on earth well within a day, including the time it takes for authorization, for close to half a century.

You're presuming that it's solely for weapons delivery. The first application that came to my mind was reconnaisance. It's all well and good to be able to deliver a warhead to "any location on earth well within a day", but intel as near-real time as you can get it is just a

You have no clue... A mach 6 fighter/bomber would very much be useful in the armament. At that speed it can outrun most missiles used to shoot it down. Very few weapons platforms can track and engage an aircraft flying faster than mach 4 at the moment, let alone something flying mach 6. There are only a handful of missiles (surface-to-air or air-to-air) which can even travel mach 6 or faster, which means you can only attach from a forward vector and once it passes your position or is flying away from you, your missiles will not be able to catch the plane. This assumes that your radar system can even detect a plane that fast and can instruct the missile how to intercept the target.

Hypersonic technology isn't just blow-stuff-up research- this is closer to just plain science. It is extremely difficult to maintain stable flight over mach 5 or so, not to mention the feats in engine and materials technology required to reach such speeds. This is interesting science and engineering, so I think it is a good thing there is military interest to fund this- it is too expensive to very easily get funding otherwise.

Oh no this indeed does have a pricetag, many of them in fact and they are big. The US pays a lot of money for its armed forces, too much in my opinion. If we can criticize and cut into education for fiscal responsibility the military should be fair game too.

Its not so clear that this has much military application. Its unlikely to be stealthy at that speed - aerodynamic heating will make it very obvious in IR. I suspect the efficiency isn't very good, and it needs a rocket for initial launch. I'm sure there are some cases where it would be preferable to a spy satellite, but I think the us has stopped using SR-71s because those cases are pretty rare.

I'd love to have scramjet technology for launch vehicles, but so far they seem to be single Mach number designs,

The kids at the Air Force never got over it. Now their toys are bigger and much more expensive - but they're still fun to shoot off in a blaze of glory - never to be recovered. I love this country - and how our tax dollars get used.

Couldn't we just give the air force guys one model rocket apiece and tell them to be satisfied?